Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Cost	$ 196,072	$ 200,382
Accumulated amortization	118,361	98,586
Net balance	77,711	101,796
Contract rights and licenses [Member]
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Cost	135,932	140,242
Accumulated amortization	81,376	69,515
Net balance	54,556	70,727
Customer relationships [Member]
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Cost	24,550	24,550
Accumulated amortization	12,513	8,546
Net balance	12,037	16,004
Contract backlog [Member]
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Cost	23,600	23,600
Accumulated amortization	17,870	15,139
Net balance	5,730	8,461
Provider networks [Member]
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Cost	11,990	11,990
Accumulated amortization	6,602	5,386
Net balance	$ 5,388	$ 6,604